I'm trying to get some files off an old old mac and want to get them off the external HD which is connected by SCSI but it doesn't seem to be recognised by the mac. I tried putting my zip drive in between the two but it doesn't seem to work either. I' can't ermember how I had it set up all those years ago but I rmember there needs to be something done to the SCSI ID? I really need to get some files off there. It's running 0S 8.1 on a Performa 6200. The mac runs perfectly fine by itself with nothing connected to it. But when I connect the ext HD it comes up with a disk and flashing question mark icon.
thanks.

There is usually a SCSI ID switch on the back of SCSI drives which you can adjust. Its been a long time for me as well. I remember there used to be SCSI terminators but i dont know if they were needed in all situations.

There should be a SCSI ID switch on the back. Set it to 2 or 4. 1 and 3 are used by the computer for the internal HD and CD-ROM respectively. The Zip drive would use 5 or 6 depending what you set it to on the back. You might live without a terminator if it's just one device.

Make sure the HD is terminated properly. As DK says , there is usually a switch at the back to turn the termination on or off. If there isn't one there , then you have to use an active terminator.Also this only applies if the external HD is the last device on that SCSI chain.
The other thing you have to do is connect them both , turn them both off , then turn on the HD, then the Mac in that order for the Mac to see the external HD.

Stewie

Edit : Yeah , I forgot the SCSI ID issue too. Thanks brains.

if you are getting the "where's my disk?" icon on power-up with the SCSI drive attached, then there are three possible answers -- the drive (or the enclosure) has died, the SCSI device ID is set to 0. 3 or 7 (all reserved by the Mac itself), or there is no termination. If you do not have an external SCSI terminator block (which should always go on the other SCSI connector) then plug in the Zip drive after it, and turnon the Zip drive's terminator switch.

Gee, it's been a while since we've had a SCSI question on these forums.

Stewie

Thanks, I don't think it's an ID problem as I haven't changed any settings and it worked fine last time I used it (about 8 years ago). I think I may need a terminator. Apart from that I'm not sure what else I could do... is there something to do with the HFS and HFS+ thing? I remember i had problems with that when I First set up the ext HD. Oh it's so confusing and really getting the old memory to work...

Is the external HD spinning up OK? As Brains/Curra mentioned the Zip drive has a termination switch so plug this is on the end to terminate the chain (and double check they're not the same SCSI ID). Internal and external SCSI devices are on different chains so if you continue to get the flashing disk icon once properly terminated I would suspect the drive to be dead.

The Performa 6200 should be fine booting from HFS or HFS+ volumes; 68K macs can read, but not boot from HFS+ volumes.

Funnily enough I've been playing around with SCSI a lot lately stewie, having found my old HD20SC external hard disk case, pulled the 20 megger and replaced it with a 9.1GB IBM It's going to be my main backup of Classic apps.

JB

I'll have to check it out and get back to you.. thanks everyone for your advice.

I have a 20MB Apple SCSI HD as well, - vintage '88 I recall, and about $1500 back then.

I haven't used mine for a very long time, but I do recall that in the mid 90's when I still used an SE/30, that the Ext HD often wouldn't start, I could hear the drive spinning, but it was not recognized by the Mac. The fix was to disconnect it, and hold it in both hands, and give it several quick 90 degree twists in both directions. The purpose being to free up the drive heads that became stuck in the parked position. - It worked a treat. If you haven't used yours for 8 years, then this could be the problem !

Is that called doing the SCSI dance Jim ?
I have a similar fix for a CRT 20" Studio display connected to my 6500. It tends to fade out every now and then but a quick tap on the right hand side brings it back OK. Not hi-tech but it works.
20mb ! WooHoo. Back in the day , that would have been a big hard drive.

Stewie

Got an old SCSI CD-RW sitting at home. 2x or 4x if I remember. Burning CD's on my old performa :P